Revisions log for Answer #706

You need to elaborate on all the factors, including wall and floor color and texture.

Example: If I plan four fixtures for 7 x 1.5 = 10.5 m², I need about 250 lumens per fixture (for ideal lighting), assuming 100 lux, which the vast majority of cheap LEDs can handle. For public buildings, however, 200 lux is assumed for corridors (which is already extremely bright for home), but if my fixtures are 1000 lumens each, then two planned by the electrician is sufficient, assuming we are talking white walls that help distribute the light evenly. You see, it's an equation with many variables.